Audio Systems: 98 sebring lxi stereo wiring, chrysler sebring, infinity sound

Question
Hi, i have a 98 Chrysler sebring lxi. it comes stock with a Mitsubishi infinity sound system. i previously owned a lx model so stereo installation was simple. my problem is that i have all the wiring codes and installed the stereo with the stock system turned on as well. problem is when i wired the stereo i had 4 wires left over and the left side speakers seem to have a lower output than the rest. speakers are not blown. 2 of the 4 wires were connected to a small black piece which seemed to connect to somewhere inside the dash, it seems it broke off when i pulled the wiring harness out. these two wires were white/blue and black/blue. same as 2 of the wires going to the stereo already. i put them with the other two and connected and the left side seems to work a little better but now check engine light is on and says its problem with the computer and i still have a green/brown and green/yellow wire remaining. wondering if i have ruined my car by attempting to install my radio? or if its a coincidence because light took 2 days to come on. any help you could give me would be great, thank you for listening

Answer
just unplug the battery to reset the computer and turn off the check engine light

about the radio you need to use the blue wire from the radio to turn on the factory infinity amplifiers, at the moment only the tweters are working because the get the power from the radio

good luck